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line2d.h
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2 // Copyright 2016 Pixar
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24 #ifndef GF_LINE2D_H
25 #define GF_LINE2D_H
26 
27 /// \file gf/line2d.h
28 /// \ingroup group_gf_BasicGeometry
29 
30 #include "pxr/pxr.h"
31 #include "pxr/base/gf/vec2d.h"
32 #include "pxr/base/gf/api.h"
33 
34 #include <float.h>
35 
37 
38 /// \class GfLine2d
39 /// \ingroup group_gf_BasicGeometry
40 ///
41 /// Basic type: 2D line
42 ///
43 /// This class represents a two-dimensional line in space. Lines are
44 /// constructed from a point, \p p0, and a direction, dir. The direction is
45 /// normalized in the constructor.
46 ///
47 /// The line is kept in a parametric represention, p = p0 + t * dir.
48 ///
49 class GfLine2d {
50 
51  public:
52 
53  /// The default constructor leaves line parameters undefined.
55  }
56 
57  /// Construct a line from a point and a direction.
58  GfLine2d(const GfVec2d &p0, const GfVec2d &dir ) {
59  Set( p0, dir );
60  }
61 
62  double Set(const GfVec2d &p0, const GfVec2d &dir ) {
63  _p0 = p0;
64  _dir = dir;
65  return _dir.Normalize();
66  }
67 
68  /// Return the point on the line at \p ( p0 + t * dir ).
69  /// Remember dir has been normalized so t represents a unit distance.
70  GfVec2d GetPoint( double t ) const { return _p0 + _dir * t; }
71 
72  /// Return the normalized direction of the line.
73  const GfVec2d &GetDirection() const { return _dir; }
74 
75  /// Returns the point on the line that is closest to \p point. If \p t is
76  /// not \c NULL, it will be set to the parametric distance along the line
77  /// of the returned point.
78  GF_API
79  GfVec2d FindClosestPoint(const GfVec2d &point, double *t = NULL) const;
80 
81  /// Component-wise equality test. The starting points and directions, must
82  /// match exactly for lines to be considered equal.
83  bool operator ==(const GfLine2d &l) const {
84  return _p0 == l._p0 && _dir == l._dir;
85  }
86 
87  /// Component-wise inequality test. The starting points, and directions
88  /// must match exactly for lines to be considered equal.
89  bool operator !=(const GfLine2d &r) const {
90  return ! (*this == r);
91  }
92 
93  private:
94  GF_API
95  friend bool GfFindClosestPoints( const GfLine2d &, const GfLine2d &,
96  GfVec2d *, GfVec2d *,
97  double *, double *);
98 
99  // Parametric description:
100  // l(t) = _p0 + t * _length * _dir;
101  GfVec2d _p0;
102  GfVec2d _dir;
103 };
104 
105 /// Computes the closets points between two lines.
106 ///
107 /// The two points are returned in \p p1 and \p p2. The parametric distance
108 /// of each point on the lines is returned in \p t1 and \p t2.
109 ///
110 /// This returns \c false if the lines were close enough to parallel that no
111 /// points could be computed; in this case, the other return values are
112 /// undefined.
113 GF_API
114 bool GfFindClosestPoints(const GfLine2d &l1, const GfLine2d &l2,
115  GfVec2d *p1 = nullptr, GfVec2d *p2 = nullptr,
116  double *t1 = nullptr, double *t2 = nullptr);
117 
119 
120 #endif // GF_LINE2D_H
double Normalize(double eps=GF_MIN_VECTOR_LENGTH)
Definition: vec2d.h:263
bool operator!=(const GfLine2d &r) const
Definition: line2d.h:89
GLdouble l
Definition: glew.h:9122
GF_API GfVec2d FindClosestPoint(const GfVec2d &point, double *t=NULL) const
Definition: vec2d.h:63
GF_API bool GfFindClosestPoints(const GfLine2d &l1, const GfLine2d &l2, GfVec2d *p1=nullptr, GfVec2d *p2=nullptr, double *t1=nullptr, double *t2=nullptr)
GfLine2d(const GfVec2d &p0, const GfVec2d &dir)
Construct a line from a point and a direction.
Definition: line2d.h:58
double Set(const GfVec2d &p0, const GfVec2d &dir)
Definition: line2d.h:62
GfVec2d GetPoint(double t) const
Definition: line2d.h:70
const GfVec2d & GetDirection() const
Return the normalized direction of the line.
Definition: line2d.h:73
PXR_NAMESPACE_CLOSE_SCOPE PXR_NAMESPACE_OPEN_SCOPE
Definition: path.h:1245
GLuint GLfloat GLfloat GLfloat GLfloat GLfloat GLfloat GLfloat GLfloat GLfloat t1
Definition: glew.h:12681
GLdouble GLdouble GLdouble r
Definition: glew.h:1406
#define PXR_NAMESPACE_CLOSE_SCOPE
Definition: pxr.h:83
GfLine2d()
The default constructor leaves line parameters undefined.
Definition: line2d.h:54
GF_API friend bool GfFindClosestPoints(const GfLine2d &, const GfLine2d &, GfVec2d *, GfVec2d *, double *, double *)
bool operator==(const GfLine2d &l) const
Definition: line2d.h:83
GLdouble GLdouble t
Definition: glew.h:1398
#define GF_API
Definition: api.h:40